1. Field of the Invention
The present invention relates to cards for storing confidential information. More particularly, the present invention relates to a card, especially a credit card, bank card, or the like, which has a security feature that prevents unauthorized use of the card.
2. Description of the Related Art
Plastic cards having electronically stored data are widely used to perform a large variety of tasks, from being used as conventional credit or bank cards to use as a security key to operate a door lock. Other types of cards are gas cards, building, room and/or elevator security access cards, personnel cards, Automated Teller Machine (ATM) cards, debit cards and cash cards. For purposes of this application, however, these cards will be generically referenced as "authorization cards" or just "cards."
Authorization cards are generally either magnetic, electronic "smart cards," or passive electronic. For magnetic cards, information particular to the rightful card owner, i.e. confidential information, is typically stored in a magnetic strip located on the back side of the card. In order to complete a given transaction, the confidential information stored on the card is directly transmitted from the magnetic strip to a card reader for recognition and authorization. With regard to smart cards and passive electronic cards, the confidential information is stored electronically and is transmitted to a card reader. Though smart cards contain a power supply, passive electronic cards do not.
However, confidential information, such as credit card number, expiration date, Personal Identification Number (PIN) and name of card owner, may inadvertently become available to other parties. Fraudulent and unauthorized use of authorization cards has cost card users and issuers (such as VISA, MASTERCARD, AMERICAN EXPRESS, and DINERS CLUB), as well as entities that accept credit cards as a form of payment for goods and services, a great deal of money.